Unable to type in ionic text box

I have login screen with username and password text fields. I have used ionic input type text. I have applied following css to make parent div horizontally & vertically center.

.wrapper {
    position: absolute;
    top: 50%;
    left: 50%;
    -webkit-transform: translateX(-50%) translateY(-50%);
    -moz-transform: translateX(-50%) translateY(-50%);
    -ms-transform: translateX(-50%) translateY(-50%);
    -o-transform: translateX(-50%) translateY(-50%);
    transform: translateX(-50%) translateY(-50%);         
} 

When I remove this class I can type in textbox of android device. But when I add this class I unable to type in textboxes of android device. Keyboard opens properly but do not show text on typing. Text shows properly on textbox focus out. Whats an issue??